Bug 828137, part 2 - Make [[Set]] always fail on window elements. With this change, `window[0] = null;` is a TypeError in strict mode code. r=bz.

--HG--
extra : rebase_source : 10066af913c07b01a701b49915ca54e4131d702b

dom/base/nsGlobalWindow.cpp

@@ -915,9 +915,9 @@ nsOuterWindowProxy::set(JSContext *cx, JS::Handle<JSObject*> proxy,
 {
   int32_t index = GetArrayIndexFromId(cx, id);
   if (IsArrayIndex(index)) {
-    // Reject (which means throw if and only if strict) the set.
-    // XXX See bug 828137.
-    return result.succeed();
+    // Reject the set.  It's up to the caller to decide whether to throw a
+    // TypeError.  If the caller is strict mode JS code, it'll throw.
+    return result.failReadOnly();
   }
 
   return js::Wrapper::set(cx, proxy, receiver, id, vp, result);

dom/base/test/test_window_indexing.html

@@ -42,6 +42,12 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=823228
   is(x.contentWindow, window[0], "First frame should have correct window");
   is(y.contentWindow, window[1], "Second frame should have correct window");
 
+  // set() hook test
+  throws(TypeError, function () {
+    "use strict";
+    window[1] = "FAIL strict";
+  });
+
   // set() hook test
   window[1] = "FAIL";
   is(window[1].name, "y", "Second frame is still y");
@@ -71,6 +77,10 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=823228
   is(window[1], undefined, "We should not have a value here either");
 
   // More set() hook test
+  throws(TypeError, function () {
+    "use strict";
+    window[1] = "FAIL3 strict";
+  });
   window[1] = "FAIL3";
   ok(!("1" in window), "We shouldn't allow indexed expandos");
   is(window[1], undefined, "We should not have a value for an indexed expando");

dom/imptests/failures/html/html/browsers/the-window-object/mochitest.ini

@@ -3,7 +3,6 @@
 support-files =
 
 
-[test_window-indexed-properties-strict.html.json]
 [test_window-named-properties.html.json]
 skip-if = true # bug 859075
 [test_window-properties.html.json]

dom/imptests/failures/html/html/browsers/the-window-object/test_window-indexed-properties-strict.html.json

@@ -1,4 +0,0 @@
-{
-  "Indexed properties of the window object (strict mode) 1": true,
-  "Indexed properties of the window object (strict mode) 2": true
-}

testing/web-platform/meta/html/browsers/the-window-object/window-indexed-properties-strict.html.ini

@@ -1,8 +0,0 @@
-[window-indexed-properties-strict.html]
-  type: testharness
-  [Indexed properties of the window object (strict mode) 1]
-    expected: FAIL
-
-  [Indexed properties of the window object (strict mode) 2]
-    expected: FAIL
-